Anatomical pouch (3)
I believe the answer is:
sac
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">anatomical pouch</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sac that I've seen before include "Animal or vegetable pouch" , "Pouchlike structure" , "Bag-like cavity" , "Bodily cavity enclosed by a membrane" , "Bodily pouch" .)